The invention concerns an engine air brake device for a 4-stroke reciprocating-piston internal combustion engine that has at least one intake valve per cylinder and two exhaust valves that are connected to an exhaust train and can be actuated via a valve bridge and a rocker arm that acts on the valve bridge and can be controlled by a camshaft either directly or indirectly via a push rod, each exhaust valve being biased in a closing direction by means of a closing spring, whereby a throttling device is installed in the exhaust train and can be actuated for engine deceleration such that an exhaust back pressure builds up in the accumulated exhaust gas upstream of the throttling device and becomes engine-internally active for engine deceleration in conjunction with a special braking device.
The invention is based on EP 0736672 B1. This reveals a procedure for engine deceleration with a 4-stroke reciprocating piston internal combustion engine which has an engine-internal braking device associated to an exhaust valve. The exhaust valve can be controlled by a rocker arm either directly or indirectly via a push rod. The parts of the braking device are shown as being integrated either in the rocker arm or in the area of the push rod. However, for engines with more than two valves no solution is suggested.
It is therefore an object of this invention to provide an engine air brake device for a 4-stroke reciprocating-piston internal combustion engine which has at least one intake valve and two exhaust valves per cylinder, which engine air brake device makes it possible to realize an engine braking process similar to that described in EP 0736672 B1.